There is a community QA (=Quality Assurance) testing for all apps in the Extras repos. This is how we make sure that only well tested and functional apps can reach end users. Here is the full process, the end of which involves the actual voting for apps. At first, an app goes to Extras-devel: this is a place where developers can share early (untested/pre-release) software with other developers and early testers. Any developer can promote his app to the Extras-testing repo if he feels like it. This means that he finds it ready enough for Extras and all it needs is some testers to confirm its quality. Members of the community can vote for apps in Extras-testing if they tested it and found it working. With a certain number of votes, the app goes to the Extras repository and end users.